Virtually all automotive vehicles are provided with automotive air environment regulating systems, which almost always include heating systems, and also often include air conditioning systems. Virtually all such systems include a blower, driven by an electric motor, for circulating the air which is to be heated or cooled. Some systems include more than one blower. The amount of heat is generally regulated by a heat control valve which regulates the supply of hot liquid coolant from the engine to a heat exchanger which heats thc air.
Most air conditioning systems are activated and deactivated by an electrically operable air conditioning clutch which is connected between an engine-driven pulley and an air conditioning compressor. The amount of cooled or heated air is usually controlled by changing the speed of the blower motor.
Typically, such systems include duct work containing movable doors or diverters for directing air into the passenger cabin through high or low outlets, and through windshield outlets which direct air against the Windshield for defogging and defrosting purposes. Such doors or diverters are often operated by vacuum motors which selectively receive their motive power from the engine vacuum.
The present invention relates to control mechanisms for such systems. Such control mechanisms are generally of the type comprising three manually operable controls, including a manually movable selector control member, a manually movable heat control member, and a manually movable blower switch control member which operates the blower speed control switch.
The selector control is employed to select the function or functions to be performed by the system. For different systems, the selector control may have different numbers of positions, according to the complexity of the system. Thus, for example, a complex system may require seven positions to select seven functions, including OFF, MAXIMUM AIR CONDITIONING, NORMAL AIR CONDITIONING, BI-LEVEL AIR CONDITIONING, VENTILATION, HEAT, and DEFROST. For a less complicated system, the selector control may have five positions to select five functions, including OFF, AIR CONDITIONING, HEAT, HEAT WITH DEFROST, and DEFROST, for example. In a system without air conditioning, the selector control may select the five functions of OFF, VENTILATION, BI-LEVEL, HEAT and DEFROST, for example.
To select the various functions, the selector control member generally operates electrical switches, vacuum switches, or both, often combined into a single unit referred to as a vacuum-electric switch. Whatever the number of function positions, it is desirable to provide detent means for detaining the selector control in each of its function selecting positions.
One object or accomplishment of the present invention is to provide a new and improved selector control having a convertible detent mechanism, which is convertible between a plurality of different numbers of detent positions. In the disclosed embodiment, the detent mechanism is convertible between seven and five detent positions, for example. The present invention is not limited to this particular selection of detent positions, but may be arranged to select other numbers of detent positions. The present invention makes it possible to convert the detent mechanism, to match the number of detent positions to the number required by different function control switches. In this way, production economies are achieved.
The selector control mechanism may include a manually movable knob which is pivotally connected to the front end of a selector control lever which is both swingable and longitudinally slidable relative to first pivot means, so that the knob may be caused to travel along a substantially straight path. The heat control mechanism may include a heat control knob, pivotally connected to the front end of an operating lever, which is also pivotally and slidably movable, so that the heat control knob is movable along a substantially straight path, parallel with the path of the selector knob.